Finding affordable PCIe options for sound aficionados.

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For years, we've trumpeted the benefits of discrete sound cards. They simply sound better than the typical integrated audio on motherboards, especially for those with discerning ears and halfway-decent speakers or headphones. Good sound cards tend to last through multiple upgrade cycles, too. They're amazingly inexpensive considering the expected lifespan. Indeed, the two we'll be putting under the microscope today—Asus' Xonar DGX and DSX—sell for less than $50.

If the names look familiar, that's because the cards are the PCI Express versions of the Xonar DG and DS. Those older models have PCI interfaces, like an awful lot of other sound cards, and PCI slots are quickly disappearing from modern motherboards. The Xonar DGX and DSX drop into any PCIe x1 slot, and those should be with us for a good, long time.

Each card has a unique character. The DGX courts headphone users with a dedicated amplifier and Dolby Headphone surround-sound virtualization. Meanwhile, the DSX offers home-theater users a replaceable OPAMP, support for more output channels, and the ability to encode multichannel digital bitstreams in real-time.

How do the two compare, and more importantly, how good do they sound? We've conducted a mix of performance, signal quality, and blind listening tests to find out. We've also thrown in our favorite mid-range sound card, the Xonar DX, and a motherboard with Realtek's latest audio codec. This should be interesting.

The Tech Report

Before we dig into the Xonars, it's worth taking a moment to expand on why sound cards tend to last so long. To be frank, the market for them has largely stagnated.

Games used to drive the demand for hardware-accelerated audio, but that feature has all but disappeared from recent titles. Creative's EAX positional audio scheme died years ago. OpenAL was supposed to be a replacement of sorts, but Creative's list of games with OpenAL audio hasn't been updated since 2008. Blue Ripple Sound's Rapture3D positional audio software is used by some Codemasters games, and it's been made to work with a handful of OpenAL titles. However, Blue Ripple Sound is quite explicit about the fact that its algorithms run on the CPU.

The fact is today's multi-core processors have an abundance of horsepower. Crunching numbers for positional audio shouldn't be a challenge. These days, developers typically handle positional audio processing in software. Some, like Battlefield 3 maker DICE, even offer their own virtualization voodoo.

Perhaps because the need for hardware acceleration has waned, the flow of new audio processors has slowed to a trickle. We've had plenty of output channels and real-time encoding options for quite some time, leaving few reasons for fresh silicon.

The older audio processors that dominate the market are designed for the PCI interface, which is quickly falling out of favor among motherboard makers. Intel dropped PCI support from its consumer desktop platforms years ago, forcing board makers to employ third-party silicon if they want to offer PCI slots. Most still do, but it probably won't be long before the majority of new boards are PCIe-only.

Since the C-Media audio processors used in the Xonar line lack native PCIe support, Asus has taken to using bridge chips to link up with the newer interface. The DGX and DSX both feature PLX's PEX8112 bridge chip, just like the other PCIe members of the ever-growing Xonar family. Bridged solutions aren't quite as slick as native ones, of course, but we've yet to see any issues related to Asus' use of the PLX chips.

In the picture above, you can see the bridge chip next to C-Media's Oxygen HD CMI8786 audio processor on the Xonar DGX. That's the same C-Media chip as on the older DG model. Likewise, the DSX features the same Asus AV66 audio processor as the Xonar DS. Though Asus' name is silkscreened on the surface, the AV66 is actually a C-Media CMI8788. Asus tells us the AV66, AV100, and AV200 processors featured on its Xonar cards are all variants of the CMI8788 with different software packages.

We're at a loss as to why Asus doesn't have its own name branded across the CMI8786. That chip is a custom order just for the Xonar DG and DGX. The CMI8786 is really just a cut-down version of the CMI8788. Both chips can handle 24-bit audio, but the CMI8788 does so at sampling rates up to 192kHz, while the CMI8786 tops out at 96kHz.

As the model numbers suggest, the CMI8788 can feed eight output channels, while the CMI8786 is capped at six. Translation: the Xonar DSX can power 7.1-speaker home theaters, while the DGX is limited to 5.1-speaker setups.

Asus uses a different mix of complementary digital-to-analog and analog-to-digital conversion silicon on each card. The DSX pairs a six-channel Wolfson DAC with a stereo codec from the same company. Cirrus logic supplies the conversion hardware for the DGX, which uses a similar DAC-and-codec combo. Incidentally, all of the DAC and codec chips offer 24 bits of resolution at 192kHz sampling rates. The Xonar DGX's 96kHz limitation comes from its audio processor alone.

The published signal-to-noise ratios of each card give us a general sense of their overall signal quality. Looks like the Xonar DGX might be the more balanced of the two; it has a 105-decibel output SNR and a 103-dB input SNR. The DSX has higher output SNR, at 107 dB, but its 100 dB input SNR is a little low.

The Xonar DGX is the less expensive of the two cards, but by less than the cost of a super-sized McDonald's combo. Deciding between the two may be more a factor of whether you intend to hook up the card to a fancy home-theater receiver or run it through a headset or headphones. We'll explore the features tailored to each setup as we take a closer look at each card.

76 Reader Comments

Whatever happened to the HDMI-out soundcards of a few years ago? That's what I want. Sure, your videocard can do that now, but not if you're doing DL-DVI or Displayport for your video. Most mid-level receivers nowadays don't even have 5.1 or 7.1 analog inputs so this computer stuff feels more and more archaic.

how good is the Echo cancellation? Was there any tests looking at that?

Skype and Jabber Video for Telepresence (CISCO product) do pretty well, but some other flash based video conferencing apps really don't do well in the echo area. I can even kill skype echo if my mom on the other end pumps up her audio, so something better than software echo cancellation would be nice.

I can't say I really understand all the graphs...but what I took away was that base sound quality is no better, and sometimes worse, than onboard. So...I still don't understand the point of a discreet sound card anymore.

I'm still using my Auzentech Prelude X-Fi PCI card. It has lasted me many years of wonderful sound, especially with gold connectors. I'm hard pressed to change the card. I think I will on my next upgrade through due to PCI slot most likely disappearing.

I actually just purchased a Recon3D from Creative about a week ago. I have an Asus M3A32-MVP Deluxe motherboard, it featured Realtek audio... but I had quite a few issues with it... It did not have a way to use Dolby Live (and I'm using a home theater system for audio, so real time DTS was important to me), and the blackhawk software used to control it was absolutely horrible, random bugs and crashes across multple windows versions/installs.

The Recon3D was locally available (I can be impatient) and had S/PDIF out (which is lacking in many sound card solutions). I can say with certainty that positional audio absolutely does sound better with Dolby Live enabled. The software controlling it is a bit heavier than realtek was, but its much more stable and user friendly. It was a great purchase.

One thing that I hadn't realized is that you can put a PCIe X1 into an X16 slot. It looks shady, but works great.

Shouldn't budget sound cards be on their way out like low end discrete GPUs? I mean, CPU's have more than enough spare cycles to throw at sound processing, and if people really needed fancy effects, wouldn't it pay to invest a bit more and go for a higher end sound card?

I can't say I really understand all the graphs...but what I took away was that base sound quality is no better, and sometimes worse, than onboard. So...I still don't understand the point of a discreet sound card anymore.

Damage spells it out pretty clearly

Quote:

The Realtek audio falls off a cliff much earlier than the Xonars in the frequency response graph. It has higher noise and distortion levels, too, with huge spikes at higher frequencies.

Quote:

The ALC898 repeats its early exit in the frequency response plot, and its high noise and distortion levels persist

This is when you push the sample rate and bit rate above 16-bit/44.1kHz. Whether or not this level of distortion or noise is noticeable to the average listener through the average monitor soundbar or set of £15 PC speakers is debateable, but the onboard solution is measurably inferior to the add-in cards for a number of use-cases.

I'd be interested in hearing how the use of a small add-on DAC such as this or this, fed by the digital output of an onboard audio solution, compares with the add-in cards for audio quality.

1) Outputs: I've had a set of Klipsch ProMedia v2.400 speakers for 12 years now and they require a front and back output. Also, I have an optical connection out to my surround sound receiver to watch online stuff on the plasma. The onboard sound card on my mobo provides both at the same time (looks like the DSX forces you to choose between rears and optical out; unless I mis read that in the article).

2) Laziness: I have a SB Live! Gold card sitting at home and I rather like having all the extra airflow available in my case without another card mucking up my setup. Also, the onboard audio works with the front audio ports for headphones when needed.

With all that said, the inherit hiss from my speakers (pickup from the mobo i'm sure) drives me batty sometimes. The optical output doesn't have that issue of course, but my normal speakers sure do. It's refreshing to hear that newer on-board solutions don't have that issue.

After reading this article though, it may be time to upgrade my sound card...I can swing $50 for the DSX...funny how only $9 seperates the "low end" card from the "high end"; used to be more like $50-$100!

I can't say I really understand all the graphs...but what I took away was that base sound quality is no better, and sometimes worse, than onboard. So...I still don't understand the point of a discreet sound card anymore.

Damage spells it out pretty clearly

Quote:

The Realtek audio falls off a cliff much earlier than the Xonars in the frequency response graph. It has higher noise and distortion levels, too, with huge spikes at higher frequencies.

Quote:

The ALC898 repeats its early exit in the frequency response plot, and its high noise and distortion levels persist

This is when you push the sample rate and bit rate above 16-bit/44.1kHz. Whether or not this level of distortion or noise is noticeable to the average listener through the average monitor soundbar or set of £15 PC speakers is debateable, but the onboard solution is measurably inferior to the add-in cards for a number of use-cases.

I'd be interested in hearing how the use of a small add-on DAC such as this or this, fed by the digital output of an onboard audio solution, compares with the add-in cards for audio quality.

I stand corrected. I was obviously not scanning the graphs close enough, I only noticed the wall at 18k...

Of course for my use, the only speakers capable of using the additional quality are hooked up thorugh a reciever with HDMI audio out on the video card...so I still don't have a use for a discrete sound card. Though for people listening through the analog outs, with good headphones or stereo amps I do now see the benifit.

I can't say I really understand all the graphs...but what I took away was that base sound quality is no better, and sometimes worse, than onboard. So...I still don't understand the point of a discreet sound card anymore.

Also, page 5 has the blind listening tests, where they consistently didn't like the sound of the onboard Realtek sound as much as the others.

I have an old Audigy 2 zs that wasn't hooked up for a long time, and going from my onboard realtek sound back to it was fantastic! I forgot how much of the sound I was missing even with my otherwise halfway decent setup.

Any internal sound card is still gonna be subjected to a metric shit ton of EMI/RFI and possibly other nasty power/interference issues, ground loops anyone? While I appreciate the update on soundcards, and those come with some really great chips, I probably won't ever touch an internal or on-board card again.

Fantastic thorough review, akin to what I usually expect from sources like Anandtech, not the Tech Report. I'll be keeping an eye out, since I've found the Tech Report to have generally less complete reviews than other sites.

Anyway, to add to this: I've had a Xonar D2X since Semptember 2008. It still uses the underlying CMI8788 chipset used here in the DSX, but in the AV200 specification (not the AV66 used here). It offers 118db input and output and even today, 4 years later, is easily the best pure performance sound card available, bar none. Whether this reinforces the fact that sound processors really haven't advanced much, or that we're simply reaching the pinnacle of what human ears can possibly distinguish, I have no idea. However, it makes me feel good that my £180 purchase 4 years ago is still top in class. Let it be so for many to come.

Multi-channel audio is such a pain in the ass on computers, and I blame Dobly. If you want multichannel from a game, you have 2 options; mulit-channel analog output or Dolby Digital Live (DDL). Very few stereo receivers are supporting 5.1 or 7.1 analog in, and very few cards support DDL. I have a 6 year old turtle beach card that has DDL, so I can run a TOSLINK cable to my reciever and play games in 5.1. If it wasn't for DDL, I would be stuck with stereo.

And don't get me started on Mac. Back in the day you could use a firewire to multichannel analog from Griffin, but driver support ended with leopard.

With out DDL, soundcards, due to Dolby licensing, cannot encode multichannel digital streams. If the stream is already encoded, as is the case with DVD or Blueray, the can pass the stream to the digital output, but if the stream needs to be constructed realtime, as it would in a game, you need an encoding license from Dobly, and that is expensive.

Multi-channel audio is such a pain in the ass on computers, and I blame Dobly. If you want multichannel from a game, you have 2 options; mulit-channel analog output or Dolby Digital Live (DDL). Very few stereo receivers are supporting 5.1 or 7.1 analog in, and very few cards support DDL. I have a 6 year old turtle beach card that has DDL, so I can run a TOSLINK cable to my reciever and play games in 5.1. If it wasn't for DDL, I would be stuck with stereo.

And don't get me started on Mac. Back in the day you could use a firewire to multichannel analog from Griffin, but driver support ended with leopard.

With out DDL, soundcards, due to Dolby licensing, cannot encode multichannel digital streams. If the stream is already encoded, as is the case with DVD or Blueray, the can pass the stream to the digital output, but if the stream needs to be constructed realtime, as it would in a game, you need an encoding license from Dobly, and that is expensive.

Whatever happened to the HDMI-out soundcards of a few years ago? That's what I want. Sure, your videocard can do that now, but not if you're doing DL-DVI or Displayport for your video. Most mid-level receivers nowadays don't even have 5.1 or 7.1 analog inputs so this computer stuff feels more and more archaic.

^ This. Discrete sound cards aren't worth a damn to most people precisely because you can't "merge" HDMI with an optical or co-ax audio signal. However, these cards are very useful for people like myself with older speakers or friends of mine that might do some hardcore recording/mixing.

However, I have to disagree with the author on his last point: The most important thing in a discrete sound card is not the audio quality. The most important thing is driver stability and that's a place where Asus stumbles pretty consistently with their sound card line. I'm running a Xonar DX in my rig right now and the manufacturer's drivers caused blue screens, audio glitches, system hitches and lacked the ASIO support they were supposed to come with. I'm running hacked drivers right now and they work great. But it always blows me away how supposedly thorough reviews like this consistently neglect the basics, like driver stability. Oh well.

Multi-channel audio is such a pain in the ass on computers, and I blame Dobly. If you want multichannel from a game, you have 2 options; mulit-channel analog output or Dolby Digital Live (DDL). Very few stereo receivers are supporting 5.1 or 7.1 analog in, and very few cards support DDL. I have a 6 year old turtle beach card that has DDL, so I can run a TOSLINK cable to my reciever and play games in 5.1. If it wasn't for DDL, I would be stuck with stereo.

And don't get me started on Mac. Back in the day you could use a firewire to multichannel analog from Griffin, but driver support ended with leopard.

With out DDL, soundcards, due to Dolby licensing, cannot encode multichannel digital streams. If the stream is already encoded, as is the case with DVD or Blueray, the can pass the stream to the digital output, but if the stream needs to be constructed realtime, as it would in a game, you need an encoding license from Dobly, and that is expensive.

1) Outputs: I've had a set of Klipsch ProMedia v2.400 speakers for 12 years now and they require a front and back output. Also, I have an optical connection out to my surround sound receiver to watch online stuff on the plasma. The onboard sound card on my mobo provides both at the same time (looks like the DSX forces you to choose between rears and optical out; unless I mis read that in the article).

Actually, when talking about 5.1/7.1, the speakers that you normally think of as rear channels are actually the surround channels. The "rear"s are a second set of optional surround speakers (they're rarely used except for giving more depth to sounds moving around behind the listener). It wouldn't have any affect on your old-school quadraphonic set-up.

With all that said, the inherit hiss from my speakers (pickup from the mobo i'm sure) drives me batty sometimes. The optical output doesn't have that issue of course, but my normal speakers sure do. It's refreshing to hear that newer on-board solutions don't have that issue.

After reading this article though, it may be time to upgrade my sound card...I can swing $50 for the DSX...funny how only $9 seperates the "low end" card from the "high end"; used to be more like $50-$100!

Yup I have the same issue, I have one of the first 7.1 chips from Creative, and the sound distortion drives me insane sometimes, but my Intel X58 mobo doesn't line up with my case (nor does any ports that I have, I have a custom case) so if I wanted to line up my slots properly it would be much better with a dedicated sound card rather than try and jury rig my on board mobo analog ports.

Hi,I don't question the place of such a topic on Ars (sound card review), i actually quite enjoy it. However, publishing a complete copy of the Tech Report article doesn't give ma any reason to read Ars. The article have a better layout over TechReport : they have a table of content, from which you can switch directly to the section you're looking for, instead of having to browse through pages only identified by page numbers.

Seriously, media convergence is one thing, I think Ars can still manage to have its own original content...

I'd like to know if these cards support digital out (with DTS) and analog out at the same time. I have a PC connected o desktop speakers and a stereo at the same time and I don't want to toggle between the two. Hardly any reviews mention these kinds of limitations.

1) Outputs: I've had a set of Klipsch ProMedia v2.400 speakers for 12 years now and they require a front and back output. Also, I have an optical connection out to my surround sound receiver to watch online stuff on the plasma. The onboard sound card on my mobo provides both at the same time (looks like the DSX forces you to choose between rears and optical out; unless I mis read that in the article).

Actually, when talking about 5.1/7.1, the speakers that you normally think of as rear channels are actually the surround channels. The "rear"s are a second set of optional surround speakers (they're rarely used except for giving more depth to sounds moving around behind the listener). It wouldn't have any affect on your old-school quadraphonic set-up.

Good catch qchronod! That detail didn't even click with me. Well then, perhaps the DSX is in my future build after all. I'm shooting for a black friday build (saving my pennies now) so i'll add this to my wishlist.

Heh, old school. I remember I was getting all kinds of flak from my college friends when I bought a 4.1 setup instead of a proper 5.1. How quickly that stopped when they actually heard the speakers

^ This. Discrete sound cards aren't worth a damn to most people precisely because you can't "merge" HDMI with an optical or co-ax audio signal.

Well, you can, at your stereo. My low-end Sony receiver has an option to use a particular optical or coax input for sound with each HDMI input, precisely when you don't want/can't use the HDMI sound. You just need to run separate video and audio cables between the PC and the stereo.

I'd like to know if these cards support digital out (with DTS) and analog out at the same time. I have a PC connected o desktop speakers and a stereo at the same time and I don't want to toggle between the two. Hardly any reviews mention these kinds of limitations.

My D2X supports this, so I believe there should be no problems with supporting this scenario in the DSX (unless it's a software limitation of the "AV66" variant of ALC8788 instead of the "AV200" variant my D2X has). However, I can't say the same of the cheaper 8786 variant, since I have no idea if it's physically supported on that.

Anyone know of a PCIe card that is in this range (or still consumer) that supports both OS X and Windows? Been wanting to do analog out surround for a while with games on both sides. My Firewire (supported in OS X only) audio solution failed a while back and I've yet to find a replacement.

^ This. Discrete sound cards aren't worth a damn to most people precisely because you can't "merge" HDMI with an optical or co-ax audio signal.

Well, you can, at your stereo. My low-end Sony receiver has an option to use a particular optical or coax input for sound with each HDMI input, precisely when you don't want/can't use the HDMI sound. You just need to run separate video and audio cables between the PC and the stereo.

True enough. However, personally I'd rather not hassle with it as I've had problems with doing that in the past.

I can't say I really understand all the graphs...but what I took away was that base sound quality is no better, and sometimes worse, than onboard. So...I still don't understand the point of a discreet sound card anymore.

Damage spells it out pretty clearly

Quote:

The Realtek audio falls off a cliff much earlier than the Xonars in the frequency response graph. It has higher noise and distortion levels, too, with huge spikes at higher frequencies.

Quote:

The ALC898 repeats its early exit in the frequency response plot, and its high noise and distortion levels persist

No you're mixing things up. The RMAA tests are driving a line out, but the listening tests are driving a pair of headphones. They're actually testing very different things: the listening test is the quality of the headphone amplifier, the RMAA tests the unloaded performance (==line out).

You can't compare the two results as they'll generally be quite different, with some devices great in one but terrible in the other. Its actually really unfortunate that the reviewer mixed up the two tests like that, would have been much more interesting to see if the blind listening tests and matching headphone out RMAA graphs.

Multi-channel audio is such a pain in the ass on computers, and I blame Dobly. If you want multichannel from a game, you have 2 options; mulit-channel analog output or Dolby Digital Live (DDL). Very few stereo receivers are supporting 5.1 or 7.1 analog in, and very few cards support DDL. I have a 6 year old turtle beach card that has DDL, so I can run a TOSLINK cable to my reciever and play games in 5.1. If it wasn't for DDL, I would be stuck with stereo.

And don't get me started on Mac. Back in the day you could use a firewire to multichannel analog from Griffin, but driver support ended with leopard.

With out DDL, soundcards, due to Dolby licensing, cannot encode multichannel digital streams. If the stream is already encoded, as is the case with DVD or Blueray, the can pass the stream to the digital output, but if the stream needs to be constructed realtime, as it would in a game, you need an encoding license from Dobly, and that is expensive.

Yes, but can games encode to PCM via the HDMI? My understanding is that without DDL, you cant make (encode) the multicannel PCM/AC3 stream. You can only pass an existing stream.

Yes, they can. HDMI is treated no differently than any other analog 5.1 interface, at least on both my (video) cards. The software (game, player, anything) just sees it as a 5.1-capable device. No issues.

It's only with SPDIF that you wind up with the issue you're talking about, because SPDIF can't handle 5.1 PCM streams; it needs encoding (such as DDL or DTS) to compress it, and that requires licensing.

I have a sound card because I have an Astro Mixamp, which requires DDL for 5.1 input. Someday motherboard manufacturers will get on board and start including DDL and the DTS equivalent (at least on enthusiast boards) and then sound card manufacturers will be in a world of hurt.

Too funny I actually just bought the DGX for my HTPC because I don't have HDMI yet -- not upgrading both TV and receiver until they die. I got the card because it was one of 2 or 3 on newegg that was half height and had optical output, the price didn't hurt either. No complaints at all, my OTA HD looks great and is in 5.1 Dolby Surround, can't ask for more.

I don't care much for soundcards. Since I also don't care much for 3D audio in games (it's been hit and miss at best) I just feed the onboard audio via SPDIF to my AV receiver with real 5.1 HT speaker setup. Most movie modes add enough spice to the sound for me in games, and the quality for music and movies is best I can get for the money.

My receiver is brand new, but it sucks so this doesn't work. I mean, it does work in theory, it supports multichannel PCM out. But for whatever reason switching between a PCM output and any encoded stream (like Dolby Digital) kills the output until I reboot.

Sucks because I use Windows Media Center for my DVR needs, which (unlike XBMC and other players) doesn't have any option to decode the stream to the 5.1 "analog" (HDMI PCM) output. It always switches to SPDIF output, killing the audio.

So for now I'm still stuck using my motherboard's optical out (luckily XBMC will re-encode on the fly all the videos that are in 6-channel AAC and such).

EDIT: Actually, this could easily be a driver issue as well, and have nothing to do with my receiver.